Enable Custom Touch Bar to show up for all apps ONLY when touchbar is empty

Would like to suggest that a custom touch bar (e.g. a Now Playing widget) shows up when the touchbar is empty in unsupported apps or in certain views like Finder on the Desktop. Customising this for every single app, including new ones every single time does not seem very intuitive or efficient. Thanks.

As far as I know, there is no way to know whether an app has Touch Bar support or not.